The optical set-up

A typical optical system is shown in Fig. 26. A lens of short focal length (7-10 cm) projects a nearly parallel beam of radiation from the source A through a filter F, to remove unwanted radiation. The stop Sj prevents unfiltered radiation from reaching the RV. It is sometimes useful to converge the beam slightly with a second lens (focal length 40 cm) such that the beam reaches its smallest diameter in the centre of the RV. The latter may be divided into two compartments, one of which contains a compound used for actinometry, or alternatively the beam is focused by the lens L3 onto a photocell or thermopile P. The intensity of the beam is suitably reduced by the density filter F2. To provide maximum possible intensity 

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The thermal expansion of Torlon between 4.2 and 295 K was measured by means of the dilatometer described in Section 13.2. The sample was a cylinder 8.2 mm in diameter and 3 cm long. The optical set up for the interferometric measurement of the thermal expansion is that shown on Fig. 13.1. 

The active part of the optical set-up starts with the entrance slit, on which light produced by the sample (the light source) is focused. The slit width is not less than 10 pm because a minimum light intensity passing through is required. The... 

Due to the inability to deposit eleetrochemically stable gate-insulating materials for GaAs, another approach was developed based on amorphous silicon (a-Si), prepared as a thin layer for LAPS devices on transparent glass substrates [40]. The diffusion length in this material was reported to be as small as 120 nm [41] and a resolution down to 1 gm has been demonstrated, which was mainly limited by the optical set-up. The electrochemical properties of the a-Si-based structures were investigated later with a LAPS device thus, the above results for SPIM were transferred back and proved for the LAPS, too [42,43]. 

It should be pointed out that, in good part because of the use of large off-axis mirrors, optical aberrations can lead to significant curvature of the images under certain instrumental configurations. This has a detrimental impact on spectral resolution when multiple rows are birmed. Pelletier et al. have reported a data processing procedure to minimize this effect for situations where experimental limitations prevent improving the optical set-up [9]. In future commercial... 

Figure 5.1 Automatic sample deposition device for TLC and a system to read the plate. Left, programmable applicator Linomat IV. Right, densitometer measuring the light either reflected or transmitted by the plate. The optical set up is similar to that of a UV/visible spectrometer (model Scanner 3, reproduced courtesy of Camag).

Figure 13.1 Kirchhojf s line reversal experiment. The schematics for the optical set-up (collimator, objective), have been simplified for reasons of clarity. See text for explanations.

Fig. 4.13 Schematic representation of the optical set-up (a) and hemispherical cell (b) forTIR Raman microspectroscopy. TIR Raman spectra of Mn(TMPyP) at the toluene/water interface with two different concentrations of dihexadecyl phosphate (DHP) in the organic phase are shown in (c). The band at 394 cm" corresponds to the symmetric breathing mode of the porphyrin ring. The spectral features were normalized by the toluene band at 520 cm . The spectra were collected with s-polarization. Reprintedwith permission from Ref [33]. Copyright (2003)...

The thermal system includes the Warm Optics Module and the Cold Optics Module, which given the optical set-up and the optical parameters of the different optical elements calculates the transmission of the sky map through the instmment. At this point the physical properties of the instrument are defined and the Double Fourier Modulation can be performed at the Double Fourier Module. Here is where the interferograms are computed analytically for different baseline positions. If pointing errors are selected, the Pointing Errors Module generates them and they are fed to the Double Fourier Moduie. 

Scarming MALDI imaging differs from normal MALDI-MS in many aspects. InstrumentaUy, the optical set-up for focusing the laser beam, the mechanical... 

Figure 1 Scheme of the optical set up of the NDIR gas analyser. The box contains filters and detectors,... 

Figure 2.19. Schema of the optical set-up for studies of Kossel diagrams.

For a more detailed characterization of the IRP-method we will briefly discuss apparatus and experimental technique recently used to measure m- and j-dependent cross sections for the reaction K + HF(v=l,j,m) -> KF + H [7,9], Figure 1 shows a schematic drawing of the crossed molecular beams machine together with the optical set up employed to prepare HF via IRP. 

In Fig. 11, a sketch of the optical set-up for interference lithography and in Fig. 12, a picture of the largest interference lithography laboratory at Fraunhofer ISE are shown. A laser beam is split, directed with mirrors and then spatially filtered and expanded. A sample holder with the photoresist plate is positioned where the expanded beams are superimposed. A shutter defines the exposure time. Behind the spatial filters, no optical components are in the optical path in order to avoid parasitic interference effects such as Airy patterns from dust particles. The nonplanarity of the interfering beams results in a small variation of the grating periods which is tolerated for the above mentioned appfications. If one assumes symmetrical angles of incidence a, then the... 

The migration of research results of IR spectroscopy to practical applications requires a high level of spectral quality and reproducibility. Standardisation and optimisation of the measurement conditions and measurement parameters are therefore considered to be necessary prerequisites for further technological progress. In this section we will discuss systematic factors, which potentially impact the spectral quality and reproducibility, such as sample preparation, the optical set-up, the problem of water vapour absorption, and aspects of spectral and spatial resolution. 

Note The maximum error in adjustment of the optical set-up leads to an uncertainty in determining the droplet diameter by phase-Doppler technique of about 8 %. The vagueness of photography is in the order of about 6 /im. 

So far the Mie theory seems to be a powerful tool for describing the scattering behaviour of optical absorbent liquid droplets and to select the right parameters of the optical set-up in combination with a correct -d-relation. 

Furthermore, we used the optical set-up in a different way [71]. In this scheme, the A/4 wave-plate is rotated in order to produce a circularly polarized... 

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